1. Field of the Invention
This invention relates to tactile key tops for the keys of finger-operated devices such as keyboard musical instruments, typewriters, calculating machines, stenography machines, etc.
2. Description of the Prior Art
Oftentimes, keyboard operators, or performers, have a need or desire to operate their keyboards while looking elsewhere. For example, clerical personnel have text or accounting records to transcribe, and musicians have sheet music or other sights to watch. Furthermore, visually impaired persons may not have the option of looking at their keyboards at all.
With many types of keyboards, including typewriter and musical keyboards, most or all fingers are required to operate more than one key. For example, each index finger is typically used to operate six or more keys on a typewriter. On a musical keyboard, each finger may, over the course of a performance, operate dozens of keys. Without visual assistance, it is sometimes difficult to accurately change finger or hand position. To aid in orientation while the fingers are changing position, various tactile orientation systems have been proposed in the prior art.
French Patent #320,203 (Laudenbach) discloses a piano keyboard with a different tactile key top texture for each of the twelve notes within each octave. One positive aspect of this arrangement is that it allows the musician to identify any of the twelve notes without reference to any other notes.
Other prior art disclose various tactile key tops. However, twelve different tactile key tops which, when used together, satisfy the criteria outlined below have not been found in the prior art.